“I’ve heard of such cases,” nodded Craig encouragingly.

“Well, you see I became interested in the subject,” she added, “when I saw some of my own friends going down.  That’s how I came to plan the campaign in the first place.”

She paused, evidently nervous.  “I’ve been threatened, too,” she went on, “but I’m not going to give up the fight.  People think that drugs are a curse only to the underworld, but they have no idea what inroads the habit has made in the upper world, too.  Oh, it is awful!” she exclaimed.

Suddenly, she leaned over and whispered, “Why, there’s my own sister, Mrs. Garrett.  She began taking drugs after an operation, and now they have a terrible hold on her.  I needn’t try to conceal anything.  It’s all been published in the papers—­everybody knows it.  Think of it—­divorced, disgraced, all through these cursed drugs!  Dr. Coleman, our family physician, has done everything known to break up the habit, but he hasn’t succeeded.”

Dr. Coleman, I knew, was a famous society physician.  If he had failed, I wondered why she thought a detective might succeed.  But it was evidently another purpose she had in mind in introducing the subject.

“So you can understand what it all means to me, personally,” she resumed, with a sigh.  “I’ve studied the thing—­I’ve been forced to study it.  Why, now the exploiters are even making drug fiends of mere—­children!”

Mrs. Sutphen spread out a crumpled sheet of note paper before us on which was written something in a trembling scrawl.  “For instance, here’s a letter I received only yesterday.”

Kennedy glanced over it carefully.  It was signed “A Friend,” and read: 

“I have heard of your drug war in the newspapers and wish to help you, only I don’t dare to do so openly.  But I can assure you that if you will investigate what I am about to tell you, you will soon be on the trail of those higher up in this terrible drug business.  There is a little center of the traffic on West 66th Street, just off Broadway.  I cannot tell you more, but if you can investigate it, you will be doing more good than you can possibly realize now.  There is one girl there, whom they call ‘Snowbird.’  If you could only get hold of her quietly and place her in a sanitarium you might save her yet.”

Craig was more than ordinarily interested.  “And the children—­what did you mean by that?”

“Why, it’s literally true,” asserted Mrs. Sutphen in a horrified tone.  “Some of the victims are actually school children.  Up there in 66th Street we have found a man named Armstrong, who seems to be very friendly with this young girl whom they call ‘Snowbird.’  Her real name, by the way, is Sawtelle, I believe.  She can’t be over eighteen, a mere child, yet she’s a slave to the stuff.”

“Oh, then you have actually already acted on the hint in the letter?” asked Craig.

“Yes,” she replied, “I’ve had one of the agents of our Anti-Drug Society, a social worker, investigating the neighborhood.”